static void Main(string[] args)
{
var books = new BookRepo().GetBooks();
//Examples.ExampleMethod(new BookRepo());
// LINQ Extension Methods
//var query = books
// .SingleOrDefault(b => b.Title == "Harry Potter and the Philospher's Stone").Title;
//var query = books
// .FirstOrDefault(b => b.Price > 14).Title;
//var pagedBooks = books
// .Skip(2)
// .Take(3);
//foreach (var pagedBook in pagedBooks)
//{
// Console.WriteLine(pagedBook.Title + " " + pagedBook.Format);
//}
//var count = books.Count();
//Console.WriteLine(count);
//var costToBuyAllBooks = books.Sum(b => b.Price);
//var minPrice = books.Min(b => b.Price);
//var maxPrice = books.Max(b => b.Price);
//Console.WriteLine(maxPrice + " + " + minPrice);
//Console.WriteLine("Cost to buy all books: £{0}", costToBuyAllBooks);
var averageCost = books.Average(b => b.Price);
Console.WriteLine(averageCost);
}
public static void ExampleMethod (BookRepo bookRepo)
{
var books = bookRepo.GetBooks();
// Linq Query Operators
var booksUnder13Quid = from b in books // From first
where b.Price < 10 // Filter
orderby b.Title // Order
select b; // Select always at the end.
// Linq extension methods.
var booksUnder15Quid = books
.Where(b => b.Price < 15)
.OrderBy(b => b.Title)
.Select(b => b.Title); // Multiple linq queries should be broken like so...
// Select appears to take an element of the IEnumerable type and forms a new list using only that parameter?
//foreach (var book in booksUnder15Quid)
// //Console.WriteLine("{0} \t| {1} | {2}", book.Title, book.Price, book.Format);
// Console.WriteLine(book);
foreach (var book in booksUnder13Quid)
Console.WriteLine(book.Title);
}
static void Main(string[] args)
{
var books = new BookRepo().GetBooks();
//var cheapBooks = books.Where(b => b.Price < 10); // awesome!
//var cheapBooks = books.Where(b => b.Price < 10).OrderBy(b => b.Title);
//LINQ QUERY OPERATOR
Console.WriteLine("Linq Query Operator");
var cheapBooksAgain = from b in books
where (b.Price < 10)
orderby(b.Title)
select(b.Title);
Console.WriteLine("LINQ QUERY OPERATOR");
foreach (var x in cheapBooksAgain)
{
Console.WriteLine(x);
}
Console.WriteLine();
//LINQ EXTENSION METHODS
var cheapBooks = books
.Where(b => b.Price < 10)
.OrderBy(b => b.Title)
.Select(b => b.Title);
Console.WriteLine("LINQ EXTENSION METHODS");
Console.WriteLine("CHEAP");
foreach (var book in cheapBooks)
{
//Console.WriteLine("Less than 10 dollars " + book.Title + " " + book.Price);
Console.WriteLine(book);
}
Console.WriteLine();
Console.WriteLine("Single/Default");
var singleOrDefault = books.SingleOrDefault(b => b.Title == "Abdul Bari");
Console.WriteLine(singleOrDefault != null); // True, i.e. yes the book is in there
Console.WriteLine();
Console.WriteLine("First/Default");
//var first = books.First();
var first = books.First(b => b.Title == "Mosh Hamedani");
Console.WriteLine(first.Title + " " + first.Price);
var firstOrDefault = books.FirstOrDefault(b => b.Title == "Mosh Hamedani");
Console.WriteLine(firstOrDefault.Title + " " + firstOrDefault.Price);
Console.WriteLine();
Console.WriteLine("Skip/Take");
var skipTake = books.Skip(2).Take(3);
foreach (var x in skipTake)
{
Console.WriteLine(x.Title + " " + x.Price);
}
Console.WriteLine();
Console.WriteLine("MIN/MAX");
var minPrice = books.Min(b => b.Price);
Console.WriteLine(minPrice);
var maxPrice = books.Max(b => b.Price);
Console.WriteLine(maxPrice);
Console.WriteLine();
Console.WriteLine("Sum");
var totalPrices = books.Sum(b => b.Price);
Console.WriteLine(totalPrices);
Console.WriteLine();
Console.WriteLine("Average Price");
var avgPrice = books.Average(b => b.Price);
Console.WriteLine(avgPrice);
// filter collections
// without LINQ
//var cheapBooks = new List<Book>();
//foreach (var book in books)
//{
// if (book.Price < 10)
// {
// cheapBooks.Add(book);
// }
//}
}
